docs: improve TypeScript navigation/discoverability (#86938)

Add signposts and info about next-env.d.ts. Also rework links from
getting started to TypeScript features, and from the to config
reference.

Author: icyJoseph

docs/01-app/01-getting-started/01-installation.mdx

@@ -330,7 +330,7 @@ You can enable the plugin in VS Code by:
 
 </AppOnly>
 
-See the [TypeScript reference](/docs/app/api-reference/config/next-config-js/typescript) page for more information.
+See the [TypeScript reference](/docs/app/api-reference/config/typescript) page for more information.
 
 ## Set up linting
 

docs/01-app/01-getting-started/02-project-structure.mdx

@@ -44,7 +44,7 @@ Top-level files are used to configure your application, manage dependencies, run
 | [`.env.development`](/docs/app/guides/environment-variables)                 | Development environment variables (should not be tracked by version control)       |
 | [`eslint.config.mjs`](/docs/app/api-reference/config/eslint)                 | Configuration file for ESLint                                                      |
 | `.gitignore`                                                                 | Git files and folders to ignore                                                    |
-| `next-env.d.ts`                                                              | TypeScript declaration file for Next.js (should not be tracked by version control) |
+| [`next-env.d.ts`](/docs/app/api-reference/config/typescript#next-envdts)     | TypeScript declaration file for Next.js (should not be tracked by version control) |
 | `tsconfig.json`                                                              | Configuration file for TypeScript                                                  |
 | `jsconfig.json`                                                              | Configuration file for JavaScript                                                  |
 

docs/01-app/03-api-reference/05-config/01-next-config-js/typescript.mdx

@@ -1,18 +1,36 @@
 ---
 title: typescript
-description: Next.js reports TypeScript errors by default. Learn to opt-out of this behavior here.
+description: Configure how Next.js handles TypeScript errors during production builds and specify a custom tsconfig file.
 ---
 
 {/* The content of this doc is shared between the app and pages router. You can use the `<PagesOnly>Content</PagesOnly>` component to add content that is specific to the Pages Router. Any shared content should not be wrapped in a component. */}
 
+Configure TypeScript behavior with the `typescript` option in `next.config.js`:
+
+```js filename="next.config.js"
+module.exports = {
+  typescript: {
+    ignoreBuildErrors: false,
+    tsconfigPath: 'tsconfig.json',
+  },
+}
+```
+
+## Options
+
+| Option              | Type      | Default           | Description                                                      |
+| ------------------- | --------- | ----------------- | ---------------------------------------------------------------- |
+| `ignoreBuildErrors` | `boolean` | `false`           | Allow production builds to complete even with TypeScript errors. |
+| `tsconfigPath`      | `string`  | `'tsconfig.json'` | Path to a custom `tsconfig.json` file.                           |
+
+## `ignoreBuildErrors`
+
 Next.js fails your **production build** (`next build`) when TypeScript errors are present in your project.
 
 If you'd like Next.js to dangerously produce production code even when your application has errors, you can disable the built-in type checking step.
 
 If disabled, be sure you are running type checks as part of your build or deploy process, otherwise this can be very dangerous.
 
-Open `next.config.js` and enable the `ignoreBuildErrors` option in the `typescript` config:
-
 ```js filename="next.config.js"
 module.exports = {
   typescript: {
@@ -24,3 +42,17 @@ module.exports = {
   },
 }
 ```
+
+## `tsconfigPath`
+
+Use a different TypeScript configuration file for builds or tooling:
+
+```js filename="next.config.js"
+module.exports = {
+  typescript: {
+    tsconfigPath: 'tsconfig.build.json',
+  },
+}
+```
+
+See the [TypeScript configuration](/docs/app/api-reference/config/typescript#custom-tsconfig-path) page for more details.

docs/01-app/03-api-reference/05-config/02-typescript.mdx

@@ -80,6 +80,17 @@ Next.js generates global helpers for App Router route types. These are available
 
 </AppOnly>
 
+## `next-env.d.ts`
+
+Next.js generates a `next-env.d.ts` file in your project root. This file references Next.js type definitions, allowing TypeScript to recognize non-code imports (images, stylesheets, etc.) and Next.js-specific types.
+
+Running `next dev`, `next build`, or [`next typegen`](/docs/app/api-reference/cli/next#next-typegen-options) regenerates this file.
+
+> **Good to know**:
+>
+> - We recommend adding `next-env.d.ts` to your `.gitignore` file.
+> - The file must be in your `tsconfig.json` `include` array (`create-next-app` does this automatically).
+
 ## Examples
 
 ### Type Checking Next.js Configuration Files
@@ -470,7 +481,7 @@ If you'd like Next.js to dangerously produce production code even when your appl
 
 If disabled, be sure you are running type checks as part of your build or deploy process, otherwise this can be very dangerous.
 
-Open `next.config.ts` and enable the `ignoreBuildErrors` option in the `typescript` config:
+Open `next.config.ts` and enable the `ignoreBuildErrors` option in the [`typescript`](/docs/app/api-reference/config/next-config-js/typescript) config:
 
 ```ts filename="next.config.ts"
 import type { NextConfig } from 'next'